in locallib.php [375:386]
public function get_files(stdClass $submission, stdClass $user) {
$result = array();
$fs = get_file_storage();
$files = $fs->get_area_files($this->assignment->get_context()->id, 'assignsubmission_onenote',
\local_onenote\api\base::ASSIGNSUBMISSION_ONENOTE_FILEAREA, $submission->id, 'timemodified', false);
foreach ($files as $file) {
$result[$file->get_filename()] = $file;
}
return $result;
}